Railway car brake mechanism



Jan. 21, 1969 E. G. GOODS RAILWAY CAR BRAKE MECHANISM Sheet- Filed Jan.26, 1967 4 INVENTOR. Z'b/t A/Qfl 6. Q1060:

ATTORNE n- 1969 E. G. GOODS RAILWAY CAR BRAKE MECHANISM Sheet 2' ofFiled Jan. 26, 1967 INVENTOR. thaw/Pp Q 5000:

Jan. 21, 1969 E. G. GOODS RAILWAY CAR BRAKE MECHANISM Sheet 3 of ATTORNg Flled Jan 26, 1967 Jan. 21, 1969 E. e. GOODS 2 RAILWAY CAR BRAKEMECHANISM Filed Jan. 26, 1967 Sheet 4 of 7 47 INVENTORI [bk 4P0 6 $000520a {7'4 m L ma, ewfl fif dw Jan. 21, 1969 G, GQODS RAILWAY CAR BRAKEMECHANISM Sheet 5 of Filed Jan. 26, 1967 v M 5 m HI Ra 5 00 N 1 ma R w:M w. m m? u 0 I\ M 0 9 Arr m W M, w M Fm. w W m M i- Jan. 21, 1969 E.a. GOODS RAILWAY CAR BRAKE MECHANISM Sheet 6 of Filed Jan. 26, 1967INVENTOR. film/P0 6. 611005 W, M JMJ 4 7' TOP/V5 X E R ml rp.

Jan. 21, 1969 Filed Jan.. 26, 1967 E. G. GOODS 3,422,931

RAILWAY CAR BRAKE MECHANISM I Sheet 7 of 7 q E1 (Q N -N k s E w L L.. ll

L L 1 L Q a g 3 N m 9 ,4 TTOPA/EYS.

United States Patent 8 Claims ABSTRACT OF THE DISCLOSURE Railway brakedevice having brake discs rigid with car wheels, and brake means in theform of toggle joint mechanisms with rods movable into alignment forbraking actions against these discs by the action of air pressurecylinders and pistons therein having connections to articulatedadjoining ends of these rods by means of piston rods. Springs in thesecylinders resist the movements of the pistons of the toggle jointmechanisms for braking actions. A swivel connector is provided betweenadjoining ends of the corresponding pair of rods in each toggle jointmechanism. The rods of the corresponding toggle joint mechanism and thecorresponding piston rod are pivotally connected at spaced points to thecorresponding swivel connector.

The present invention relates to railway car brake mechanisms,especially of the freight type, and is an improvement upon theinventions shown and described in Busch US. Patents 2,903,096, 2,903,097and 2,903,098. The present application is a oontinuation-in-part ofapplication Ser. No. 417,658 filed Dec. 11, 1964, now US. Patent No.3,307,659.

In the application of railway brakes by power derived from air underpressure, a single air storage reservoir is usually employed for eachrailway car for the operation of the brakes on the two trucks of thecar. As the air under pressure is discharged from the reservoir duringthe application of the brakes, the pressure progressively decreases dueto the expansion of the air. It is important that as the air pressuredecreases, the braking force increases, to compensate for this decreasein air pressure and to assure thereby that the braking force applied iseffective.

A toggle joint mechanism is highly desirable for the application ofrailway brakes because it has the characteristic of progressivelyincreasing its mechanical advantage, as the articulated arms of themechanism move towards alignment. However, the rate of increase ofmechanical advantage of the toggle joint mechanism is high, especiallytowards the terminal phase of its braking stroke, so that the decreasein the rate of air pressure used to power such a mechanism would beovercompensated by this mechanism. As a result, the sudden increase ofbraking power applied by the air-powered toggle joint mechanism duringthe terminal phases of the braking stroke of the mechanism, isexcessively shocking to the railway car and the other cars of the train.

One object of the present invention is to provide new and improvedair-powered toggle joint means, which apply the brakes to a railway car,and which avoid the disadvantages described.

To obtain the objective described, each toggle joint mechanism ispowered by a fluid power unit, comprising an air cylinder into which airunder pressure from the main pressure air reservoir of the car isdelivered upon application of the brakes. Acting against powertransmitted to the toggle joint mechanism by the air in said aircylinder is a coil spring. This coil spring is progres- Patented Jan.21, 1969 "ice sively compressed during the braking stroke, and reducesprogressively thereby, the power transmitted to the toggle brakemechanism during its braking stroke. The resultant power transmitted bythe toggle joint mechanism during its braking stroke will be leveled offby the progressively counteracting effect of the coil spring, so thatthe braking power transmitted by the toggle joint mechanism to the brakeshoes is substantially more uniform during its stroke than would be thecase in the absence of such a coil spring.

As a further feature, the coil spring also serves to return the togglejoint mechanism and its associated movable parts into inoperativeposition away from braking position upon release of the brakes, so thatthe brake shoes are moved away from the braking surfaces of the brakesystem.

Another object of the present invention is to provide a railway brakesystem with toggle joint mechanisms designed to apply substantiallyconstant braking pressures, regardless of wear on the brake shoes.

A further object of the present invention is to provide a new andimproved hand-operated transmission system, employable as an alternativeto a fluid-operated power applying system, for operating the togglejoint mechanism of a railway brake system.

Various other objects, features and advantages of the present inventionare apparent from the following description and from an inspection ofthe accompanying drawings, in which FIG. 1 is a top plan view of arailway car truck having a braking system constituting an embodiment ofthe present invention;

FIG. 2 is a top plan view of part of the railway car truck shown in FIG.1, but on a larger scale;

FIG. 2a is a perspective of the end of an equalizer bar forming part ofthe support structure for the braking system;

FIG. 3 is a section of the railway car truck taken on lines 33 of FIG.2;

FIG. 4 is a detail section of the brake system taken on lines 44 of FIG.2;

FIG. 5 is a detail section of the brake system taken on lines 5-5 ofFIG. 2;

FIG. 6 is a detail section of the railway car truck taken on lines 6-6of FIG. 1;

FIG. 7 is a detail section of the railway car truck taken on lines 77 ofFIG. 6;

FIG. 8 is a detail section of the brake system taken approximately onlines 8-8 of FIG. 4;

FIG. 9 is a top plan view of part of one of the equalizer bars formingpart of the support structure for the braking system;

FIG. 10 is a top plan view of part of the other equalizer bar formingpart of the support structure for the braking system;

FIG. 11 is the end view of the equalizer bar shown in FIG. 9;

FIG. 12 is an end view of the other equalizer bar shown in FIG. 10;

FIG.13 is a detail section taken on lines 13-13 of FIG. 9;

FIG. 14 is a detail section taken on lines 1414 of FIG. 12;

FIG. 15 is a view partly in side elevation and partly in section of thefluid power unit operable to power one of the toggle joint mechanisms ofthe brake system, the view being taken approximately along the lines15-15 of FIG. 16;

FIG. 16 is a partial end view of the fluid power unit shown in FIG. 15;

FIG. 17 is a graph showing the force in the air brake cylinder due toair pressure for different travels of the piston operating the togglejoint mechanism;

FIG. 18 is a graph showing the braking force on a brake disc by a togglejoint mechanism operating without a return spring for different travelsof the piston operating said mechanism;

FIG. 19 is a graph showing the force delivered by the piston resisted bya return spring and operating the toggle joint mechanism, said forcebeing shown for different travels of said piston; and

FIG. 20 is a graph showing the braking force on the brake disc due tothe force delivered by the toggle joint mechanism operating with areturn spring.

Referring to FIGS. 1-3 of the drawings, there is shown a railway freightcar truck comprising a pair of side structures or frames havingrespective guide openings 11 to receive the ends of a conventional truckbolster 12 extending between said frames and projecting at the ends intosaid openings, where they are supported on coil springs (not shown) andare guided by side columns 13 of said openings for verticalshock-absorbed movement. The bolster 12 is provided at its ends withlugs 14 engaging the inboard sides of the side columns 13 of the sideframes 10 and lugs (not shown) engaging the outboard side of the sidecolumns. These lugs 14 guide the bolster 12 for vertical movement.

The bolster 12 is also provided with a center conformation 16 for directpivotal connection to the underside of the railway car body in aconventional manner. Between the two side frames 10 and supportedthereon by suitable bearings are two parallel axles 17 carrying onopposite ends, flanged car wheels 18 which ride on rails 19.

To support certain operating parts of the brake mechanism land at thesame time to sustain the side frames 10 against the stresses of thebraking action, there are provided two equalizer bars 20 and 20a (FIGS.1-14) on opposite sides of the bolster 12, each bar being pivotallyconnected at its ends by means of hinge pins 21 to brackets 22 integralor otherwise fixedly secured to the side frames.

The side frames 10 are shown of the conventional type employed withbrake mechanisms having brake beams with their ends slidable in guideson the inboard sides of said side frames. In the specific shown, thesebrake beam guides are defined by the brackets 22, and since these guidesusually slant downwardly towards each other, the equalizer bars 20 and20a, which are in the form of channels, correspondingly slanttransversely of their longitudinal direction towards each other, asshown in FIG. 3 with their open sides facing downwardly.

For the pivotal attachment of the ends of the equalizer bars 20 and 20ato the brackets 22, the ends of the bars are cut away to form tongueextensions 23 at the ends, as shown in FIGS. 2 and 2a, and a block 24 issnugly fitted at each end to provide a bearing for the correspondinghinge pin 21 as shown in FIGS. 2, 2a, 6, 7, 9, 11 and 13.

The equalizer bars 20 and 20a secured to the side frame brackets 22through the hinge pins 21 as described, assist the bolster 12 inmaintaining the truck side frames 10 in alignment or parallel to therespective rails. The equalizer bars 20 and 20a and the truck sideframes 10 form a parallelogram, and since these are pivotally joinedthrough the brackets 22 and the hinge pins 21, they operate as aparallel motion permitting the side frames to shift relatively endwi-seand into limited angular positions with respect to the equalizer bars 20and 20a when the wheels 18 are rounding a curve. The equalizer bars 20and 20a also serve to support the weight of the brake mechanism.

The brakes for the four car wheels 18 of each car truck are operated byfour similar brake head levers or brake support arms 25 (FIGS. 1 and 2),each pivotally secured at one end to one of the equalizer bars 20 and20a by means of a pivot or hinge pin 26, while its other end carries abrake head 27 by means of a pivot pin 28. The brake head 27 carries aface plate 30 with a brake shoe 31 for application to a brake rotor ordisc 32, which is affixed to the corresponding car wheel 18 on theinboard side thereof, to stop said disc, and which presents a brake faceon its inboard side. The construction described is similar to that shownand described in the aforesaid copending application Ser. No. 417,658.

As shown in FIGS. 1, 2, 9, 10 and 14, the lower side of each equalizerbar 20 and 20a in each of the regions where a brake head lever or brakesupport arm 25 is pivotally connected to said equalizer bar, has weldedthereto a reinforcing plate 35 and welded to said plate is a bearing 36for a corresponding hinge pin 26.

Power for operating the brakes in each car truck is derived from twosimilar individual axially aligned fluid power units 40 (FIGS. l5, 8, 15and 16) on opposite sides of the bolster 12. Each of these power units40 comprises an air cylinder 41, rigidly secured to the correspondingequalizer bar 20 and 20a with its axis horizontal and in the verticalplane extending along the length of the truck and along the railway carand through the center of the bolster 12.

For supporting each cylinder 41 on the corresponding equalizer bar 20and 20a, each of said equalizer bars is cut out to produce a recess 39into which the lower section of the cylinder extends, and the equalizerbar is reinforced where it has been weakened by this recess by an angleiron 42 welded to the underside of the equalizer bar underneath therecess. A bracket 43 with a yoke extension 44 serving the purpose to bedescribed, has base ears 45 secured to the outer inclined side webs 46of the corresponding equalizer bar 20 and 20a by bolts or studs 47, anda body 48, offset upwardly into vertical position from these base ears.Each cylinder 41 is secured to the corresponding bracket 43 by means ofbolts or studs 50 passing through the outer end wall 51 of the cylinderand through the body 48 of said bracket, and the yoke 44 extendshorizontally from said bracket body.

Each cylinder 41 includes a piston 55,slidable therein, and connected toa peripheral end ring 56 at one end of the cylinder by a reversely,progressively foldable skirt 59 made of rubber or other suitableresilient material, to seal the peripheral gap between the periphery ofsaid piston and the peripheral wall of the cylinder in all positions ofthe piston. Air is introduced into one end of the cylinder 41 on oneside of the piston 55 by means of pressure air inlet 57, and a pistonrod 58, connected to said piston, extends through the wall 51 at theother end of the cylinder, so that the piston and rod serve as a powertransmission means to the toggle mechanism. A spring 61 shown in theform of two coil units 62 and 63, one inside the other, bears againstthe piston 55 and against end wall 51, and resists the movement of thepiston as it is powered by the air pressure towards said end wall. Arelief valve 64 in the cylinder end wall 51 permits the air on one sideof the piston 55 to escape, as the air under pressure acts on the otherside of the piston.

The two inlets 57 on the two air cylinders 41 are connected to a mainair pressure reservoir or chamber (not shown) of conventional type andhaving an outlet, which is opened when the brakes are to be applied, andwhich when opened delivers air to the four cylinders 41 on the twotrucks carrying each railway car.

The power transmission between each cylinder 41 on each side of thebolster 12 and the two brake heads 27 on the same side of the bolster,comprises a toggle joint mechanism having two push rods at an angle toeach other, connected at their outer ends to the brake head levers orbrake support arms 25 respectively by means of the pivot pins 28 andarticulated at their inner adjoining ends together and to the outer endof the corresponding piston rod 58 by means of an angular swivelconnector 71, pivotally connected to said rod and guided for movementalong the yoke 44. This swivel connector 71 is channelform with twosimilar parallel opposed web plates 73 having aligned holes 74 in theapex region of the connector and is located between two oppose-d arms 72of the yoke 44 for islidable movement therealong. A hearing sleeve 75extending between the swivel connector plates 73 and the holes 74, isintegral or otherwise rigidly connected to the piston rod 58. A pivotpin 76 passes through the holes 74 and through the sleeve 75 and passeswith a slide fit through two aligned elongated slots 77 extending alongthe yoke arms 72 to guide the swivel connector 71 as well as the pistonrod 58 along said yoke arms, while permitting said connector to swivelabout the axis of said pin.

The swivel connector 71 has two angularly related arms 80 and the inneradjoining ends of the two push rods 70 of the toggle joint mechanism arepivotally connected to the outer ends of said connector arms by means ofpivot pins 81. The outer ends of these two push rods 70 are pivotallyconnected to the outer ends of the brake head levers 25 by means of thepivot pins 28.

In the operation of the brake mechanisms shown in FIGS. 1, 2 and 3, whenthe brakes are not applied, these mechanisms are in the phase positionshown in the drawings, with the brake heads 27 spaced from the brakediscs 32, due to the positive action of the springs 61 on said brakeheads through the pistons 55, the push rods 70 and the brake head levers25 carrying said brake heads.

Upon application of the brakes, air is admitted through the air inlets57 into the air cylinders, by the opening of the main valve (not shown)from the main air pressure chamber (not shown). This causes the pistons55 to be moved by braking air pressures outwardly in their cylindersaway from the bolster 12 against the action of the springs 61, and this,in turn, causes the push rods 70 to straighten out and the brake headlevers 25 to turn about the axes of their pivot pins 26 in directions toapply the brake shoes 31 to the brake discs 32 with braking pressure.

The pivotal connections between the push rods 70 and the swivelconnectors 71, and between the swivel connectors and the piston rods 58,permit the elements of the toggle joint mechanisms to adjust themselvesand to compensate automatically for uneven wear among the differentbrake shoes 31, so that regardless of such uneven wear, the brakingpressures applied by all of the brake shoes in each truck aresubstantially the same.

Upon release to atmosphere of the air braking pressure on the pistons55, the compressed springs 61, in their releasing movements positivelymove the toggle joint mechanisms in a manner to move the brake heads 27into inoperative positions away from the brake discs 32, shown in FIGS.1, 2 and 3.

In the conventional type of air pressure systems for applying airpressure for braking operations, the main air pressure chamber containsa definite volume of air under pressure before the initiation of thebraking operation, and as the elements of the braking system are movingin braking position, the pressure in the pressure chamber falls. In thesystem shown herein, as the pistons 55 move in the cylinders 41 underthe action of air pressure away from the bolster 12, the power airavailable for that purpose expands, causing thereby the force on thepistons 55 to decrease at a substantially constant rate. FIG. 17 is agraph showing this reduction in the piston force in each cylinder 41, asthis piston moves through its full stroke, which in the specific formshown would be approximately 4 inches. As a result, the braking force atthe end of the piston stroke in the absence of a restraining spring isnot ashigh as it should be.

To compensate for this progressive drop in cylinder force, a togglejoint mechanism is employed to transmit power from the cylinders 41 tothe brake head levers 25. The mechanical advantage of the toggle jointmechanism increases progressively as its two push rods 70 move towardslongitudinal alignment, as shown in FIG. 18. However, as noted in thegraph of FIG. 18, when such a toggle joint mechanism is used without arestraining spring, the rate of increase in mechanical advantage of thismechanism is high, at least during the terminal stages of brakeapplication, and consequently, the braking force during these stages isapplied at such excessive rates during these stages as to createundesirable shocks, impacts and concussions to the railway cars, andattachments thereto. If the toggle joint mechanism with its mechanicaladvantage increasing at such high rate as shown in FIG. 18, is poweredby an air cylinder having decreasing power delivery characteristics, asshown in FIG. 17, this power delivery characteristic is not onlycompensated but is overcompensated by the toggle joint mechanism, sothat the rate of delivery of braking power by the toggle joint mechanismtowards the terminal brake applying stages of its stroke is of excessiveshock producing intensity.

As a coil spring is compressed, its resistance to compression isprogressively increased, and the restraining force offered by a springto a piston operating under the conditions here contemplated wouldresult in a force delivered by the spring-pressed piston, progressivelydecreasing during the stroke, at a rate greater than the rate of forcedelivery of the piston in the absence of the restraining spring. Thedifference in rates of decrease in power delivery is apparent from acomparison of FIGS. 17 and 19.

If the toggle joint mechanism is powered by the cylinder 41 with thepiston 55 restrained by the spring 61, the resulting braking forcedelivered by the toggle joint mechanism will be almost uniform throughmost of its stroke, and at its terminal braking stages, the rate ofincrease of the braking force delivered by the toggle joint mechanismwould be comparatively slow, and certainly much slower than it would bein the absence of the restraining spring 61, as shown in FIG. 20. Theapplication of the brakes therefore will not be attended with such shockand concussion.

The brake system described can be operated in conjunction with a handbrake system, as shown in FIGS. 1, 2, 3, 4, 5, 9, l0, ll, 12 and 14.This hand brake system shown in conjunction with the air-powered brakesystem described, comprises a horizontal pull rod operated from ahand-controlled device (not shown), such as a bell crank and worm. Oneend of this pull rod 90 is pivotally connected to one end of ahorizontal lever 91 on one side of the bolster 12 by means of a pivotpin 92, the other end of this lever having a rotatable bearingconnection to the right hand pivot pin 76 adjacent to the equalizer bar20a, as shown in FIGS. 1-3. The intermediate section of the lever 91 issupported for horizontal movement on a horizontal support arm 93,secured to the top web of the equalizer bar 20a. As the lever 91 ispulled by the pull rod 90 by the actuation of the hand brake system, thelever rotates about the axis of the pivot pin 76.

The angular movement of the lever 91 on one side of the bolster 12 aboutthe corresponding pivot pin 76 is transmitted to a horizontal lever 94on the other side of the bolster by means of a horizontal connectinglink 95. This lever 94 is pivotally secured at one end by means of apivot pin 96 to an arm 97 secured to the top web of the equalizer bar20. The other end of this lever 94 has a rotatable bearing connection tothe left hand pivot pin 76 adjacent to the equalizer bar 20, as shown inFIGS. 1-3.

The connecting link extends through the bolster 12, and has pivotpin-elongated slot connections 97 and 98 at its opposite ends tointermediate sections of the levers 91 and 94 respectively, permittingsaid levers to turn about the pivot axes at these connections. A pair ofguides 100 secured to the equalizer bars 20 and 20a by means of brackets101, guide the link 95 translationally endwise crosswise of the bolster12.

In the operation of the hand brake system, when the pull rod 90 ispulled to the left (FIGS. 1, 2 and 3), the lever 91 rotates clockwiseabout the axes of the cor responding pivot pin 76, and about the pivotaxis at the connection 97, both angular movements taking place eithersuccessively or simultaneously. These angular movements of the lever 91,cause the pivot pin 76 to move along the guide yoke 44 away from thebolster 12 and cause the push rods 70 of the corresponding toggle jointmechanism to straighten out and to apply the brakes to the correspondingbrake discs 32. At the same time or subsequent or prior thereto, theconnecting link 95 is moved to the left, causing the lever 94 to elfectangular movements of this lever about the axis of its correspondingpivot pin 76 and about the pivot axis at the pivot connection 98, eitherin sequence or simultaneously, thereby effecting the movement of thispivot pin along the corresponding guide yoke 44 away from the bolster12. This operation causes the push rods 70 of the corresponding togglejoint mechanism to straighten out and to apply the brakes to thecorresponding brake discs 32.

Although the different operations of the hand brake system have beendescribed as possibly taking place in sequences, these steps, in everycase, take place substantially simultaneously, so that braking forcesare applied to all four of the brake discs 32 almost at the same time.

What is claimed is:

1. In a railway car truck, the combination comprising a pair of coaxialcar wheels, a toggle joint mechanism extending between said wheels andcomprising two rods, means articulating the inner adjoining ends of saidrods to form a toggle joint between said rods, comprising a swivelconnector, said rods being pivotally connected at said adjoining ends tosaid swivel connector at spaced points thereof, and means for confiningthe movements of the other outer ends of the rods in directions to bringsaid rods towards and away from alignment, means for applying brakingpressure to said toggle joint including a power transmission memberpivotally connected to said swivel connector at a region thereof betweensaid adjoining rod ends, and movable in a direction to bring said rodstowards alignment, and means responsive to the aligning action of saidrods for braking said wheels.

2. The combination in a railway car tnick as described in claim 1, saidmeans for applying braking pressure to said toggle joint including afluid pressure cylinder, said power transmission member constituting apiston in said cylinder movable by the pressure of the fluid deliveredto said cylinder, and a piston rod secured to said piston and pivotallyconnected to said swivel connector at said region.

3. The combination in a railway car truck as described in claim 1, saidswivel connector being in the form of an angular plate having armsdiverging from an apex region, said rods being pivotally connected attheir inner adjoining ends to the outer ends of said arms respectively,and said power transmission member being pivotally connected to the apexregion of said swivel connector.

4. The combination in a railway car truck as described in claim 2,comprising a guide yoke connected to one end of said cylinder and havingmeans for guiding said piston along said yoke in directions to move saidrods into and out of alignment and for correspondingly guiding thepivotal connection of said piston rod to said swivel connector in thelatter directions along said yoke.

5. The combination in a railway car truck as described in claim 1,comprising side frames for the truck, said car wheels being supported onsaid side frames respectively, said means for braking said wheelscomprising brake discs on the inboard sides of said wheels respectivelymounted for rotation with said wheels respectively, a pair of brake headlevers, means for pivotally supporting said levers at substantiallyfixed points with respect to said side frames, and for pivotallyconnecting said other outer ends of said rods, brake heads carried bysaid brake head levers respectively and movable towards brakingpositions as said rods are moved into alignment.

6. In a railway car truck, the combination of a pair of opposed sideframes extending along the longitudinal direction of the truck, fourwheels supported on said side frames with two wheels on each side of thetruck and with each wheel on one side coaxial with the correspondingwheel on the opposite side, the axes of said wheels extending parallelbetween said side frames and transverse to said longitudinal direction,a truck bolster extending between said side frames for support from saidside frames and located between the two pairs of coaxial wheels, andmeans for applying brakes to the wheel comprising brake discs on theinboard sides of the wheels respectively, rigid with the wheelsrespectively for rotation therewith, and presenting brake faces on theirinboard sides, a pair of toggle joint mechanisms extending between saidside frames on opposite sides of said bolster, each of said mechanismscomprising two rods articulated at adjoining inner ends out of alignmentto form a toggle joint therebetween, and means for confining themovements of the other outer ends of the rods in direction to bring saidrods towards and away from alignment, and means for applying brakingpressure to said toggle joint, including a first lever located on oneside of the bolster and extending therealong, a pull rod pivotallysecured to one end of said lever means pivotally connecting the otherend of said lever to the toggle joint on said one side of the bolster, asecond lever located on the other side of said bolster and extendingtherealong, means for pivotally supporting said second lever at one end,means pivotally connecting the other end of said lever to the togglejoint on said other side of the bolster, and a connecting link havingpivotal connections at its ends with the intermediate sections of saidlevers respectively and extending across said bolster for transmittingbraking power from said first lever to said second lever.

7. The combination in a railway car truck as described in claim 6,comprising a pair of parallel equalizing bars on opposite sides of saidbolster, extending between said side frames and pivotally connected attheir ends to said side frames, the means for pivotally supporting saidsecond lever at one end pivotally supporting said second lever on theequalizer bar on said other side of said bolster.

8. The combination in a railway car truck as described in claim 6,comprising fluid pressure power means for applying braking forces tosaid toggle joints in directions to bring each pair of articulated rodstowards alignment, said levers, link and pull rod being manuallyoperable as an alternative to said fluid pressure power means.

References Cited UNITED STATES PATENTS 3,307,659 3/1967 Goods 188-59DUANE A. REGER, Primary Examiner.

U.S. Cl. X.R. 188153

